Because in the past Phillips County has been the focus of a great deal of geologic inquiry, especially of the Pleistocene, measured sections previously reported by Hibbard et al. (1944), Byrne et al. (1948), Frye and A. R. Leonard (1949), Frye and A. B. Leonard (1954), and Frye et al. (1956) have been included, with a few exceptions. Information in brackets is from this study's interpretation of the sections. All previously reported sections were revisited, and some were found to be no longer viable, particularly streambank exposures of alluvium. Also, measured sections from this study have been included.

Shale, very thin bedded, clayey and noncalcareous; thin lenses of selenite interbedded; dark-gray to black with some yellow limonite-stained zones

30.0

Base covered

Total section measured

33.7 ft

Section measured in a cutbank along Bow Creek in NW NW sec. 35, T. 5 S., R. 17 W., immediately above the measured section of the Carlile Shale; top is eroded, but otherwise the section is typical of the stratigraphic unit as it crops out in this area (Byrne et al., 1948).

Sand and gravel, lenticular, interbedded fine and coarse with a few silty zones; contains pebbles and cobbles (up to 1 ft in diameter) of Cretaceous chalk and sand and fine gravels predominantly of quartz, feldspar, and granitic grains similar to those of the Ogallala Formation farther west; discontinuous zone of yellow-brown limonitic staining at top; at southeast end of trench is a lentil of [presumed] Pearlette volcanic ash, 2-3 ft thick, near top of this interval above high Cretaceous bedrock

Silt and sand in basal part consisting of grains and a few pebbles of chalk and chalky shale and quartz; becomes finer and more even textured upward; light red-brown at top and yellow-gray at base; massive; snails occur 10 in. above base

Acknowledgments

Appreciation is expressed to the many residents of Phillips County who provided access to their land and information concerning local geology, soils, stream systems, and historical events. D. W. May of the University of Northern Iowa and graduate students in the Department of Geography at the University of Kansas contributed many useful field observations. Two anonymous reviewers kindly provided constructive comments.

Mapping the geology of Phillips County would have proven a much more difficult task and would have taken far longer had it not been for the assistance and dedication of Alan Arbogast, co-author of the county geologic map. The Dane Hansen Foundation of Logan, Kansas, generously contributed funds for the project.